Starter for internal combustion engines



Feb. 14, 1933. w. J. BAUMAN STARTER FOR INTERNAL COMBUSTION ENGINES Original Filed Sept. 25. 1931 Bnnentor:

y Warren, JBauman w A Gfl meg Patented Feb. 14, 1933 UNITED STATES PATENT OFFICE WARREN J. BAUMAN, OF LOCK HAVEN, PENNSYLVANIA, ASSIGNOB, BY DIRECT AND MESNE ASBIGNMENTS, TO THE WEST BRANCH CORPORATION, OF WILLIAMSPOBT, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA STARTER FOR INTERNAL COMBUSTION ENGINES Application filed September 25, 1931, Serial No. 585,131. Renewed July 11, 1982.

This invention relates to improvements in starting mechanism for internal combustion engines wherem are employed a motor actuated starting shaft, an engine gear wheel for actuating and starting the engine, a primary driving pinion on the starting shaft, a secondary driving pinion actuated by the primary axis of rotation into and out of mesh with the engine gear wheel and a yieldable driving connection between the starting shaft and the primary pinion.

The object of my present invention is to improve this type of starting mechanismby re ucing the number of parts thereof, s mplifying the construction thereof, reducing the cost of the manufacture thereof and in creasing the efiiciency thereof.

With the aforesaid object in view the invention consists in the novel construction, combination and arrangement of elements hereinafter described and particularly claimed.

In the accompanying drawing, illustrating my invention,

Figure 1 is a front view, partly broken away, of a starting mechanism showing one form of embodiment of my invention.

Figure 2 is a side view thereof, partly in section, on line 2-2 of Fig. 1.

Figure 3 is a longitudinal sectional detail. showing the starting shaft and parts carried thereby.

Figure 4 is a side View of the spring pressed lever.

Figure 5 is a sectional detail, on line 5-5 of Fig. 1. I

Figure 6 is a detail in front View, showing the secondary driving pinion and ad juncts, after the pinion has been moved a short distance from its normal position toward-the engine gear.

Referring to the drawing, 3 designates a suitable frame or support in which the starting shaft 4 is journaled. This'shaft 4 i:- constructcd to be actuated by a suitable prime mover, usually an electric motor. the shaft 4 forming an outwardly projecting. extension of the armature or power shaft. thereof.

The starting shaft tcarries a primary pinion and movable transversely of itsdriving pinion 6 which is mounted to rotate thereon adjacent to the frame 3 and which is provided with an outwardly extending hub or collar 7 formed integraltherewith.

The outer or free end portion of the shaft 4 is provided with a collar 8 which is spaced from the pinion collar 7, and which is prevented from turning relatively to the shaft 4 by a suitable key 9 interposed between the shaft and the collar, as clearly shown in the drawing. Longitudinal movement of the collar 8 on the shaft 4 is prevented by a screw 10 which is screwed into the collar 8 and which is provided with a reduced inner-end portion which extends into a bore in the shaft 4. Accidental unscrewing of the screw 10 is prevented by a split ring retainer 11 which is formed of spring wire and sprung into an annular groove in the collar and ;into the slot in the outer end of the screw.

A helical spring 12 encircles the shaft 4 and extends between the collars 7 and 8. The respective ends of the spring 12 terminate in oppositely directed end portions 13 and 14 which'extend parallel to the shaft 4 and which are located within bores 15 and 16 formed in the collars 7 and 8, respectively,

and 'extendin g parallel to the shaft 4;.

The spring 12 and collars 7 and 8 provide a yieldable driving connection between the starting shaft 4 and the pinion 6, said connection causing the pinion to be turned in either direction by and with the shaft 4 as a unit when there is insuflici'ent load upon the pinion 6 to affect the spring 12, and said connection permitting a limited amount of relative rotary movement between the shaft 4 and the pinion 6, cushioned by the spring 12, when the load is sufficient to overcome the resistance of the spring to relative rotary movement between the shaft and the pinion.

The collars 7 and 8 are provided with sleeves 17 and 18, respectively, which extend toward each other and into the end portions of the spring 12 and support the central portion or main body of the spring in concentric spaced relation to the shaft. This construction permits the free action of the helices of the spring as it winds and unwinds about the shaft 4 in performing its function as a yieldable driving connection.

e arrangement of the end portions 13 and 14 of the spring 12 and the bores 15 and 16 in which they are located parallel to the shaft 4 provides a very simple and inexpensive construction, the parts of which may be easil and quickly assembled and disassem bled y sliding the pinion 6, the spring 12 and the collar 8 longitudinally onto or oil from the shaft 4 when the screw 1O is removed from the collar 8. The screw 10 forms the sole means for holding the parts in place when they are assembled on the shaft 4 and the screw 10 is prevented from accidentally leavin its applied position by the removable sp it retaining ring 11 previously described.

When the parts are assembled on the shaft 4, the spring 12 is slightly compressed longitudinally and holds the pinion 6 firmly against a shoulder on the shaft 4, the spring and shoulder preventing displacement of the pinion 6 longitudinally of the shaft 4 and permitting the free rotation thereof.

The frame or support 3 occupies a fixed relation to the frame of the engine to be started thereb and it is secured to or it may form a part 0 the engine frame which is indicated at 19 in Fig. 1. The engine is provided with a gear wheel 20 carried by its crank shaft 21 which is journaled in hearings in the engine frame, so that the gear wheel 20 will be rotated by the crank shaft when the engine is running and may be rotated to start the engine when it is idle.

The frame or support 3 has a bracket 22 formed on or secured thereto providing two spaced parts 23 and 24 between which is located a secondary driving pinion 25 in mesh with the primary pinion 6. The secondary pinion 25 is carried by a shaft 26, the resp tive end portions of which project from the sides of the pinion and into slots 27 and 28 in the parts 23 and 24 to support the pinion 25 and permit it to be rotated and moved transversel of its axis of rotation toward and from t e engine gear wheel 20 and into and out of mesh with the teeth thereof. When the pinion 25 is out of mesh with the gear wheel 20 its shaft 26 rests against one end of the slots 27 and 28, and when the pinion 25 is in full mesh with the gear wheel 20, its shaft 26 bears against the opposite end of the slots 27 and 28. The length of the slots 27 and 28 and the relation thereof to the axis of the pinion 6 are such thatthe movement of the pinion 25, occasioned by the movement of its shaft 26 from end to end of the slots 27 and 28, will not disturb the practical meshing engagement of the two driving pinions 6 and 25 with each other.

In operating the mechanism, the starting shaft 4 is rotated in the direction of the arrow in Fig. 1 and it thereby rotates the pinions 6 and 25 in the directions of the arrows in Fig. 1 and, when the inion 25 is in mesh with t e gear wheel 20, it rotates the same in the direction of the; arrow thereon in Fig. 1 to start the engine.

To enable the secondary pinion and its shaft26 to move toward primary pinion 6 and the starting shaft 4 and thereby permit the primary pinion 6 to continue 66 advance the secondary pinion into engagement with the engine gear 20 without interruption if the forward surface of a tooth of the secondary pinion 25 should strike against the rearward surface of a tooth of the engine gear 20, as shownin Fig. 6, I make the central portions of the slots 27 and 28 wider than the end portions thereof and wider than the diameter of the secondary inion shaft 26, as shown in Figs. 1 and 6. en the primary pinion 6 advances the'secondary pinion 25 into mesh the action of the pinion 6 and the weight of the pinion 25 tends to keep the pinion shaft 26 in contact with the bottom of the slots 27 and 28. If, however, the forward surface of a tooth of the pinion 25 should strike against the rearward surface of a tooth of,

the engine gear 20, before the pinion has been moved into full mesh with the engine gear, as shown in Fig. 6, the pressure of the primary pinion 6 tending to rotate the secondary pinion 25, and the opposition of the tooth of the engine gear 20 to such tendency, will cause the secondary pinion 25 to raise the shaft 26 within the widened portions of the slots 27 and 28 and move toward the primary pinion 6 and thereby cause the teeth of the pinion 25 to easily move on into full mesh with the teeth of the engine gear 20, there being sufiicient clearance provided in the spaces between the teeth of the pinions 6 and 25'to permit this limited movement of the pinion 25 toward and from the pinion 6.

o prevent the pinion 25 from being thrown backward in its line of travel if its teeth should contact with the teeth of the gear wheel 20, and to prevent the teeth of the pinion and the teeth of the engine gear from jamming and thus prevent the damage resulting therefrom when the pinion is moved into mesh with the gear wheel, I arrange the supporting and guiding slots 27 and 28 for the pinion shaft 26 in such relation to the gear wheel 20 that, when the pinion is moved from the normal position shown in Fig. 1 into mesh with the gear wheel 20, it will be moved on a line 29 which intersects a radial "line 30 projecting from the center of the gear wheel 20 and which extends from the line 29 at an acute angle thereto and toward the teeth of the gear wheel 20 which approach the pinion 25 when the gear wheel is driven thereby; and, in addition to this, I bevel the free end 31 of each tooth of the gear wheel 20 'in a direction which recedes from the cen- -ter of the gear wheel and from the forward with the engine gear 20,

tooth of the geari wheel 20, while the pinion is moving into mesh with the gearwheel.

To increase the weight of the secondary pinion 25 near the periphery thereof for the purpose of accelerating its movement into and out of mesh withthe engine gear wheel, I provide the same with a ring 33. having an exterior diameterthe full diameter of the pinion 25 and being suitably secured thereto adjacent to the ends of its teeth. v

To prevent the secondary pinion 25 from being accidentally moved from its normal position, as sho'wnin Fig. 1 whenthe starting shaft, 4 is idle, and while the starting motor coines to rest after the-pinion 25 has v been returned to the normal position by the engine gear following an engine starting op- ..eration, I provideajplate-like lever 34 fitted within a slot in thetop of the bracket part 24 and fulcrumed therein on atransversely extending-pin 35. One end portion of the I lever 34 is pressed yieldingly against the top power applied thereto.

comes into mesh with the gear wheel 20, the

of the shaft 26 by a spring 36 housed within a bore in the part 24 and acting against the bottom of the other end portion of the lover. The lever 34 bears upon. the shaft 26 in all positions thereof and it is provided with a shoulder 37 which prevents accidentalmovoment of the shaft 26 and pinion. 25- from its normal position, and which permits movement thereof toward the engine gear wheel 20 when the starting shaft 4 is rotated, as

-will be presently described..

The operation of the starting mechanism is as follows of which not only rotates the pinion .25 in the direction of the arrow in Fig. 1, buti'also moves it toward the engine gear wheel 20, guided by its shaft 26 moving in the slot27 and 28. \Vhen the shaft 26 reaches the end of the slots 27 and 28 nearest the gear wheel 20, the pinion 26 is in full mesh withthe gear wheel 20 and it is held there by the As the pinion 25 latter, which is at rest, opposes and retards the rotary movements of the pinions 6 and 25 while the driving force of the starting shaft 4 causes the spring 12 to yield and to be twisted or wound about the shaft to cash- "ion theshock of the engagement of the rotating pinion 25 with the idle gear wheel 20, and, thereafter, the pinion 25 starts and continues to rotate the gear wheel 20 until the firing withinthe engine begins. Thus the spring 12 provides a yielding driving connection between the shaft 4 and pinions 6 and 25.

When the firing withinthe engine begins the speed of the gear wheel 20 is suddenly and greatly accelerated and the speed of the pinion 25 is correspondingly accelerated and thereby caused to act against the teeth of primary pinion 6 in a manner to permit the acceleration of the gear wheel 20 to move the pinion 25 out of mesh therewith and back to the normal position, shown in Fig. 1, where it is retained by the shouldered portions 37- of the lever 34 engaging the pinion shaft 26.

Should the surface of the outer end of' a tooth of the pinion 25 encounter the surface of the beveled free end of a tooth of the engine gear wheel 20 while the pinion 25 is moving into mesh with the gear wheel, the forward bodilv movement of the pinion will be momentarily retarded thereby until the rotation of the pinion causes the said tooth thereof to clear the beveled end of the said tooth of the gear 20, whereupon the pinion will continue its forward movement on the line 29 as the next succeeding tooth thereof enters a space between two teeth of the gear wheel 20 and the pinion moves into full mesh with the gear wheel. I

During the operation of the mechanism to start the engine. the first impulse of the starting shaft 4 easily moves the pinipn shaft 26 from engagement with the shouldered portions 37 of the lever: 34 which bears lightlv against the shaft, and. after the pinion 25 has moved into mesh with the gear wheel 20, the free end portion of the lever 34 bears lightly upon the shaft 26 and permits the easy return of the pinion 25 to its normal position. I

The extent to which the spring 12 is twisted or distorted from its normal condition in cushioning the engagement of the pinion 25 with the gear wheel 20. during an engine starting operation is governed and controlled by the load or the strength of the resistance offered by the engine through the gear wheel 20 to the turning power of the pinion 25. and the spring is constructed ,with sufficient strength to enable it to perform its function vwith'the desired-yielding or cushioning 21x;- "tion as described herein.

. I claim as my invention.

. 1'. In a starting mechanism for internal combustion engines, the combination with an engine gear wheel, of a support, a starting shaft rotatable in the support, a primary driving pinion carried by the shaft, a secondary driving pinion in mesh with the primary pinion and movable under the influwith by the action ence of the startin shaft into'mesh with the engine gear, and movable under the influence of the engine gear out of mesh therewith, a shaft carrying the secondary pinion, said support having two spaced parts located on the respective sides of the secondary pinion and having slots therein into, which the last named shaft extends to be supported thereby and to guide the secondary pinion toward and from the engine gear wheel, one of said parts having a bore and an additional slot therein, a lever located within the last named slot and pivoted to said support and ada ted to bear against the last named shaft in a 1 positions thereof, and a spring within said bore pressing the lever against the last named shaft, said lever having a shoulder or engaging the last named shaft to prevent accidental movement thereof toward the enginegear whenthe starting shaft is idle.

2. In a starting mechanism for internal combustion engines, the combination with an engine gear wheel, of a support, a starting shaft rotatable in the support, a primary driving pinion rotatable on the shaft, a yieldable driving connection between said shaft and said pinion a secondary driving pinion in mesh with the primary pinion and movable thereby into mesh with the engine gear when the starting shaft is rotated, a shaft carrying the secondary pinion, and means for supporting-the secondary pinion shaft, the axis of rotation of the primary pinion being above the axis of rotation of the secondary pinion, and said means having parts provided with elongated, substantially horizontal uninterrupted surfaces extending beneath the secondary pinion shaft and over which it is rolled in supporting contact thereof the primary pinion when it moves the secondary pinion into mesh with the engine gear.

3. In a starting mechanism for internal combustion engines, the combination with an engine gear wheel, of a support, a starting shaft rotatable in the support, a primary driving pinion rotatable on the shaft, a yield ing driving connection between said shaft andsaid pinion, a secondaryvpinion in mesh with the primary pinion and movable thereby into mesh with the engine gear when the starting shaft is rotated, a shaft carrying the secondary pinion, and means for sup orting and guiding the secondary pinion s aft, the axis of rotation of the primary pinion being above the axis of rotation of the secondary pinion, said means having parts provided with elongated, substantially horizontal, uninterrupted surfaces over which the secondary pinion shaft is rolled by the action of the primary pinion when it moves the secondary pinion into mesh with the engine gear, said secondary pinion shaft being free .part, a secondary driving w1th the primary pinion an movable thereparts with umnterru co tact therewith movable t erefrom; toward the axis of the P m ry p i n 4. In a starting mechanism for internal combustion engln the combination with an engine gear-wheel of a support, a starting shaft rotatable in t e support, a primary driving pinion rotatable on the shaft, a part fixed to the'shaft, a torsional spring encircling the shaft and havin one 'end portion thereof engaged with said other end portion thereof engaged with said by from an inoperative positioninto mesh with the engine is rotated, a shaft carrying the secondary p1n1on,'means for supporting and guiding the secondary pinion shaft, and means for releasably maintaining the secondary pinion shaft in said inoperative position, the axis of rotation of the primary pinion being above the axis of rotation of the secondary pinion, and said means having parts provided with elongated, substantially horizontal, uninterrupted surfaces extending beneath the seconlillary pinion shaft and over which it is ro e action of the prlmary pinion when it moves the secondary pinion into mesh with the engine gear.

5. In a starting mechanism for internal combustion engines, the combination with an engine gear wheel, of a support, a starting shaft rotatable in the support, a primary driving pinion rotatable on the shaft and having a bore therein substantially parallel to the axis of the shaft,,a collar fixed on the shaft and having a bore therein substantially parallel to the axis of the shaft, 8. torsional spring encircling the shaft between said collar and said pinion and having one end portion thereof extending into the bore in said pinion and the other end portion thereof extending into the bore in said collar, a secondary driving pinion in mesh with the primary pinion and movable thereby from an inoperative position into mesh with the engine gear when the starting shaft is rotated, a shaft carrying the secondary pinion, means for supporting and guiding the secondary pinion shaft, said means havin parts provided with elongated, substantially horizontal, uninterrupted surfaces extending beneath the secondary pinion shaft and over which it is rolled in'supporting contact therewith by the action of the primary pinion when it moves the secondary pinion into mesh with the engine gear and means for releasably maintaining the secondary pinion shaft in said normal position. the axis of rotation of the primary pinion being above the axis of rotation of the secondary pinion.

'6. In a starting mechanism for internal pinion and the inionin mesh in supporting contact therewith by the gear when the starting shaft combustion'en 'nes, the combination with an engine gear w eel, of a support, a starting shaft rotatable in the support, a primary driving pinion rotatable on t e shaft, a yielding driving connection between said shaft and said pinion, a secondary driving inion in mesh with the primary pinion an movable thereby from an inoperative osition into mesh with the engine gear w en the starting shaft is rotated, means for supporting and guidin the secondary pinion shaft, the axis of rotation of the primary pinion being above the axis of rotation of the secondary pinion, said means comprising parts on the respective sides of the secondary pinion and provided with substantially horizontally extendin slots into which the secondary pinion shaft extends and over the bottom walls of which it is adapted to be rolled in supporting contact therewith by the action of the primary pinion when it moves the secondary pinion into mesh with the engine gear, the walls of said slots at one end thereof forming stops to limit the movement of the secondary pinion shaft to the inoperative position, and the walls of said slots at the other end thereof forming bearings for the secondary pinion shaft in the operative position thereof.

7. In a starting mechanism for internal combustion engines, the combination with an engine gear wheel, of a support, a starting shaft rotatable in the support and having a free end portion projecting therefrom and provided with a shoulder, a primary driving pinion rotatable on said end portion and bein prevented from inward displacement by said shoulder, a collar on said end portion outwardly of said pinion, a helical spring encircling said end portion between said collar and said pinion and having one end portion thereof engaged with the collar and the other end portion thereof engaged with said pinion, said spring opposing relative rotary movement between the collar and the pinion, a secondary pinion in mesh with the primary pinion and movable transversely of its axis of rotation and under the influence of the starting shaft into mesh with the engine gear, means for supporting and guiding the secondary pinion, said primary pinion and said spring and said collar being axially movable onto and ofi from said end portion, and said primary pinion being axially movable on said end portion into and out of mesh with said secondary pinion, and means for detachably securing said collar to said end portion.

8. In a starting mechanism for internal combustion en 'nes, the combination with an engine gear w eel, of a support, a starting shaft rotatable in the support and having a free end portion projecting therefrom and provided with a shoulder, a primary driving pinion rotatable on said end (portion and bemg prevented from inward isplacement by said shoulder and having a bore therein substantially parallel to the axis of the shaft, a collar on said end portion outwardly of said pinion and having a bore therein substantially parallel to the axis of the shaft, a helical spring encircling said end portion between said collar-and said pinion and having one end portion thereof extending into the bore in said pinion and the other end portion thereof extending into the bore in the collar, said spring opposing relative rotary movement between the collar and the pinion, a secondary pinion in mesh with the primary pinion and movable transversely of its axis of rotation and under the influence of the starting shaft into mesh with the engine gear, means for supporting and guiding the secondary pinion, said primary pinion and said spring and said collar being axially movable onto and off from said en portion, and said primary pinion being axially movable on said end portion into and out of mesh with said secondary pinion, and means for detachably securing said collar to said end portion.

In testimony whereof I afiix my signature.

IVARREN J. BAUMAN. 

